Y-Combinator published a new set of documents for their SAFE , short for "Simple Agreement for Future Equity". The new version takes the document from a pre-money investment to a post-money investment. But for those of you that know neither versions, a SAFE is a legal document signed by the SAFE investor and a startup, so that the startup gets cash to build their product and the investor gets equity in the company. How much equity the SAFE investor gets is not spelled out in numbers but in the form of a set of equations that should compute this number at a later stage. "Later" usually means at the next funding round called Series A, where a larger investor injects more cash into an already working prototype of the product. At the point of Series A, it is much more clear on how the product performs and whether there is a market. The Series A investment usually happens a year after the SAFE investment. The assumption here is that it is fair to both the startup and th